Many modern internal combustion engines use a radiator to dissipate heat from the engine and other systems. A typical radiator assembly includes a finned metallic core through which an engine coolant fluid is pumped. Air passing over the core dissipates heat from the fluid, and the heat is ultimately expelled to the ambient environment.
In recent years, various forces have elevated the cooling efficacy requirements for engine radiator assemblies. For example, recent and upcoming jurisdictional emissions regulations require that certain internal combustion engines, in particular diesel engines, operate with reduced output of certain emissions. As a result, various engine operating strategies have developed for reducing certain emissions; however, while some of these strategies show much promise, they can require more heat to be rejected by the engine for optimal performance than in traditional designs. The greater heat rejection requirements have in turn prompted a search for new and improved radiator assembly designs.
The more demanding requirements for radiators have thus far been addressed in several different ways. In some instances, radiators are simply made bigger, such that more surface area is available to transfer heat from the engine coolant fluid to air. While this approach is relatively straightforward, there can be significant spatial constraints inside the engine compartment of a work machine, and there are ultimately limitations on how large a radiator may be made. Often, stock radiators are already at or close to the maximum possible size of an available envelope without significantly redesigning the work machine. Moreover, increased size invariably adds weight, cost and manufacturing complexity to the work machine.
Another approach to improving radiator performance has been to increase the density of the radiator fins. In other words, more fins capable of transferring heat from the engine coolant fluid to the air are packed into a space equivalent to that available for a standard radiator. While this approach can ameliorate certain of the shortcomings of overly large radiators, it has its own set of problems. For instance, more densely packed radiator fins tend to become clogged with debris more readily. In traditional designs, organic debris such as leaves and other bits of plant matter, as well as inorganic debris such as road dust tend to pass fairly easily through the relatively widely spaced fins of the radiator core. In contrast, it can be more difficult for debris, in particular inorganic debris, to pass through the more closely packed fins of certain newer designs, reducing the heat exchange capacity of the radiator as the debris accumulates.
Debris packed in between the relatively closely spaced fins of certain modern radiator designs can reduce the ability of the radiator to transfer heat to the air, as less surface area may be available due to the insulating effect of caked-on, chalky debris, in particular inorganic debris. Filtering of both organic and inorganic debris can be done to a certain extent via particulate filters mounted on an exterior grill of the work machine. However, the relatively small size of inorganic particles, often as small as 2 microns, requires a very fine filter, which tends to cause such a pressure drop for air passing therethrough that insufficient air flow is available to the radiator itself.
Changes in overall engine system design have compounded the above problems for radiators with closely packed fins. For instance, rather than mounting a fan in front, some newer engine systems have the fan mounted between the engine and the radiator core, such that cooling air is drawn through the core rather than blown by the fan. Consequently, less air pressure is available from the fan to assist in blowing debris off of the radiator fins. Further still, where work machines used in the construction industry are concerned, the engine may often be mounted in the back. This, coupled with the fact that such machines do not typically attain particularly high ground speeds, means that relatively little air from travel of the work machine is available to blow debris from the radiator. As a result, the radiators of such work machines must typically be manually cleaned more frequently than is desirable, and more often than a typical maintenance schedule may allow.
One known approach to radiator debris problems is disclosed in U.S. Pat. No. 6,217,638 to Van de Velde. Van de Velde illustrates a process of removing debris from the grille filter of an engine, via a jet cleaner assembly that blows air tangentially to the surface of the grille. Van de Velde further describes a device for practicing the process, including an undulate filtration grille having a tangential blower and a supply of compressed air. Air is blown as desired via the tangential blower along each of a plurality of grooves in the surface of the grille filter. While Van de Velde recognizes that debris in the grille filter is undesirable, and provides one approach to the problem, the process and apparatus described are limited to certain grille types, and do not directly address the issue of debris clogging the radiator core itself.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.